JPH05177782A - Polymer film - Google Patents

Abstract

(57) [Summary] (Modified) [Structure] A polymer film comprising a base layer of a polymer material and a coating layer 2 formed from a composition containing a layered mineral and a resin obtained from a crosslinking agent. The coating layer 2 comprises 10-90% of the layered mineral by weight of this layer and 10-90% of a resin obtained from a crosslinking agent. This covering layer 2 preferably additionally comprises a copolymer of ethylene and vinyl monomers. The polymer film has an oxygen barrier property and the layered mineral coating layer exhibits improved adhesion to the polymer substrate layer. This polymer film is particularly suitable for use as a packaging film.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to polymeric films, and in particular coated polymeric films.

[0002]

Polymer films containing layered minerals are known. Layered minerals are
It has been used to impart various properties to polymer films, such as flame retardancy, antistatic properties and gas, especially oxygen, barrier properties. This is, for example, disclosed in JP-A-62-181
144, EP-A-235926 and US-A-3,
499,820. Unfortunately, the films often failed to adhere the layered minerals to the polymer substrate.

Japanese Unexamined Patent Publication No. 63-233836 discloses a film having a barrier property against steam and gas, and this film contains a laminated silicate and a vinylidene chloride resin. However, there is currently a commercial need for materials that are more environmentally acceptable than vinylidene chloride resins.

The present inventors have invented a coating film having a layered mineral capable of exhibiting oxygen barrier properties and an improved adhesion of the layered mineral coating layer to a substrate.

[0005]

[Means for Solving the Problems and Effects of the Invention]
The invention provides that the substrate layer of polymeric material comprises at least one of
On one surface, there is a coating layer formed of a composition containing a layered mineral and a resin obtained from a cross-linking agent, wherein the coating layer is more than 10% by weight, less than 90% by weight, and 10% by weight.
Provided is a polymeric film comprising greater than 90% by weight of a resin layer derived from a crosslinker.

The present invention forms a substrate layer of polymeric material, and applies a coating layer formed on at least one surface of the substrate layer from a composition containing a layered mineral and a resin obtained from a cross-linking agent. Also provides a method of making a polymer film comprising a layer of layered mineral of greater than 10 wt%, less than 90 wt% and a resin layer obtained from greater than 10 wt%, less than 90 wt% of a crosslinker.

Substrates used to make the coated polymeric films of the present invention suitably include all polymeric materials capable of forming self-supporting, opaque or preferably transparent films or sheets.

"Self-supporting film or sheet" means
It means a film or sheet that can exist independently without a supporting substrate.

The substrate of the coated film of the present invention can be formed from any film forming polymeric material. Suitable thermoplastic, synthetic materials are 1-olefins such as ethylene, propylene or butene-1, especially homopolymers or copolymers of propylene, polyamides, polycarbonates, and especially synthetic linear polyesters. The polyester may be one or more dicarboxylic acids or their lower alkyl (up to 6 carbon atoms) diesters such as terephthalic acid, isophthalic acid, phthalic acid,
2,5-, 2,6- or 2,7-naphthalene dicarboxylic acid, succinic acid, sebacic acid, adipic acid, azelaic acid, 4,4'-diphenyldicarboxylic acid, hexahydro-terephthalic acid, or 1,2-bis -P-carboxyphenoxyethane (optionally accompanied by a monocarboxylic acid such as pivalic acid) with one or more glycols, especially aliphatic glycols such as ethylene glycol, 1,3-propanediol, 1,4 Obtained by condensing with butanediol, neopentyl glycol and 1,4-cyclohexanedimethanol.

Polyethylene terephthalate films are especially preferred, and among others, in general, for example, British Patent No. 83
No. 8,708, biaxially oriented by sequentially stretching in two directions at right angles to each other at a temperature of 70 to 125 ° C.,
A film heat-set at a temperature of 150 to 250 ° C. is preferable.

The substrate comprises a polyallyl ether or its thio counterpart, especially a polyaryl ether ketone, polyaryl sulfone, polyaryl ether ether ketone, polyaryl ether ether sulfone, or their copolymers or their thio counterparts. May be. Examples of these polymers are EP-A-1879, E
Disclosed in PA-184458 and US-A-4008203, particularly suitable materials are those sold by ICI PLC under the registered trademark STABAR. The substrate may comprise poly (arylene sulfide), especially poly-p-phenylene sulfide or copolymers thereof.

Suitable thermosetting resin substrate materials include addition polymerized resins such as acrylic resins, vinyl resins, bismaleimide resins and unsaturated polyesters, formaldehyde condensation resins such as condensation products with urea, melamine or phenol, cyanate resins. , Functionalized polyester polyamides or polyimides.

The polymer film substrate for producing the coated film of the present invention may be unstretched or uniaxially stretched,
In order to obtain a satisfactory combination of mechanical and physical properties,
Preferably, they are biaxially oriented by stretching in two directions perpendicular to each other in the plane of the film. Simultaneous biaxial orientation is achieved by extruding a thermoplastic polymer tube, followed by quenching, reheating, and internal gas pressure for transverse orientation and pulling at a rate that causes longitudinal orientation. sell. Sequential stretching can be carried out in the tenter method by extruding the thermoplastic substrate material flat, followed by first stretching in one direction and then in the other mutually orthogonal directions. In general, it is preferred that the film is first stretched in the machine direction, that is, in the traveling direction by a film stretching machine, and then stretched in the transverse direction. The stretched base film may have good dimensional stability by being dimensionally constrained and heat set at a temperature higher than its glass transition temperature, which is preferable.

The thickness of the substrate is 6 to 300 μm, especially 6 to 1
00 μm, and more preferably 6 to 25 μm.

A "crosslinking agent" means that it chemically reacts during the formation of the coating layer to form a polymeric resin, preferably forming covalent bonds with both itself and the underlying surface to effect crosslinking. By a material that is formed and thereby improves adhesion to the surface. The cross-linking agent is suitably an organic material, preferably a monomer and / or oligomer species, particularly preferably a monomer species, prior to the formation of the coating layer. The molecular weight of this crosslinking agent is preferably less than 5000,
More preferably less than 2000, particularly preferably 1000
Less, particularly preferably 250-500. In addition, the crosslinker should preferably be internally crosslinkable to provide protection against solvent penetration.

Suitable crosslinking agents include epoxy resins, alkyd resins, amine derivatives such as hexamethoxymethylmelamine, and / or amines such as melamine, diazine, urea, cyclic ethylene urea, cyclic propylene urea, thiourea, cyclic ethylene thio. It may include condensation products of urea, aziridine, alkyl melamines, aryl melamines, benzoguanamines, guanamines, alkyl guanamines and aryl guanamines with aldehydes such as formaldehyde. A preferred cross-linking agent is the condensation product of melamine and formaldehyde. The condensation product may optionally be alkoxylated. It is also preferable to use a catalyst to accelerate the crosslinking action of the crosslinking agent. Preferred catalysts for crosslinked melamine formaldehyde include paratoluene sulfonic acid, maleic acid stabilized by reaction with a base, and morpholine paratoluene sulfonate.

The layered mineral is preferably a film-forming 2: 1 phyllosilicate layered mineral platelet (p).
laterets). For information on the composition and structure of phyllosilicate minerals, see “Clay Mineral
s: Their Structure, Behavior & Use ", Proceedings
of Royal Society Discussion Meeting, 9 & 10 Novemb
er 1983, London, The Royal Society, 1984 (especially 222
~ 223, 232-235).

The term "platelet," as used herein, refers to a process in which a layered mineral is subjected to a chemical delamination process to form an aqueous colloidal dispersion of high aspect ratio particles of the mineral (forming a film from the particles. It is used to mean small particles of the resulting layered mineral.

Preferably, the layered mineral is smectite, preferably hectorite and montmorillonite.
And especially from the group consisting of vermiculite.

The term "vermiculite" is used herein to refer to all materials known minerologically and commercially as vermiculite. Vermiculite ore is a naturally occurring mineral that contains a mixture of phases (eg vermiculite, biotite, hydrobiotite, etc.) and intercalation cations (eg Mg ²⁺ , Ca ²⁺ , K).
⁺ ) Mixture. The formation of an aqueous suspension or slurry of vermiculite platelets relies on ion exchange (usually incomplete) to produce the proper microscopic swelling. The swollen, fully or partially ion-exchanged vermiculite gel can then be comminuted to produce a film-forming aqueous suspension of vermiculite platelets. It is well known to treat vermiculite particles with one or more aqueous solutions of metal (especially alkali metal) salts or alkylammonium salts, followed by swelling in water and then milling to delaminate vermiculite, eg GB -A-1016385, GB-A-
1119305, GB-A-1585104, GB-A
-1539382 and US-A-4130687.

Vermiculite is a particularly suitable layered mineral when a coating film exhibiting gas barrier properties, especially oxygen barrier properties, is required. The coated film of the present invention has an oxygen permeability of less than 50 cc / m ² / day, preferably 20 cc / m ^2.
less than m ² / day, more preferably less than 10 cc / m ² / day,
Particularly preferably, it is less than 5 cc / m ² / day, and particularly preferably less than 1 cc / m ² / day.

A preferred embodiment of the present invention is more than 50% of the number of platelets, preferably 55-99.9%, more preferably 60-99%, particularly preferably 70-95%.
Particle size (which means the maximum width of the platelet) is 0.
Includes a coating of vermiculite platelets that is 5-5.0 μm. 80-99.9% of the number of vermiculite platelets, more preferably 85-99.9.
%, Particularly preferably 90 to 99.9% is a particle size of 0.1.
It is also preferable to have 5.0 μm. The average particle size of the vermiculite platelets (which means the average value of the maximum width of the platelets) is preferably 1.0 to.
The thickness is 3.0 μm, more preferably 1.2 to 2.2 μm, and particularly preferably 1.3 to 1.6 μm.

The thickness of the vermiculite platelets is preferably about 10-60Å, especially about 25-40Å. In addition, it is preferable that the thickness of the vermiculite platelets is 60 to 100%, more preferably 70 to 99%, and particularly preferably 90 to 95%. The average thickness of the vermiculite platelets is preferably 25-50Å, more preferably 25-40.
Å, particularly preferably 25 to 30 Å.

The coating layer may suitably have a substantially continuous platelet layer of any practical thickness up to 5 μm, preferably up to 2 μm, more preferably up to 0.2 μm, Coating films which exhibit desirable properties, for example surprisingly improved barrier properties against atmospheric oxygen, have very thin thicknesses, for example up to 0.01 μm, in particular 0.02-0.2 μm, in particular 0.025-. 0.1μ
m with a substantially continuous platelet layer.

The coating layer is preferably a layer of the resin obtained by the crosslinking of a cross-linking agent of more than 20% by weight and less than 80% by weight, more preferably more than 25% by weight and less than 70% by weight, particularly preferably more than 30% by weight and 60% by weight. %, Especially preferred 3
Contains more than 0% and less than 50% by weight. This coating layer preferably comprises more than 20% by weight and less than 80% by weight of a layered mineral layer, more preferably more than 30% by weight and less than 75% by weight, particularly preferably more than 40% by weight and less than 70% by weight, particularly preferably 50% by weight.
Contains more than 70% and less than 70% by weight.

In a preferred embodiment of the invention, the coating layer additionally comprises a copolymer of 1-olefin and vinyl monomer. Suitable 1-olefins include ethylene, propylene and butene-1. Ethylene is particularly preferred. The vinyl monomer is preferably a vinyl ester such as vinyl chloroacetate, vinyl benzoate, and especially vinyl acetate. Ethylene / vinyl acetate copolymers are particularly preferred. 1- present in this copolymer
The ratio of the amount of olefin to vinyl monomer is preferably 5:
1 to 1: 5, more preferably 4: 1 to 1: 2, and particularly preferably 3: 1 to 1: 1.

The presence of the copolymer of 1-olefin and vinyl monomer in the coating layer surprisingly further improves the adhesion of the layered mineral coating layer to the polymer substrate. The amount of copolymer of 1-olefin and vinyl monomer is preferably 1 to 30% by weight of the coating layer, more preferably 2 to 20%, particularly preferably 2.5 to 15%, particularly preferably 2.5. ~ 4%. The copolymer of 1-olefin and vinyl monomer is preferably mixed with the layered mineral prior to adding the crosslinker to the coating composition.

A coating composition comprising a layered mineral platelets, a crosslinker and preferably a copolymer of 1-olefin and vinyl monomer is applied as a slurry or dispersion,
Then, the dispersion medium is removed to form a cohesive layer to form a coating layer. Preferably, the dispersion medium comprises water and the slurry or dispersion comprises 0.5-20% by weight, more preferably 1-10% by weight of layered mineral platelets.

The coating layer composition may be applied before, during or after the stretching operation in the production of oriented films. The coating layer composition may be applied to the film substrate, for example, during the two stages (longitudinal and transverse) of the thermoplastic film biaxial stretching operation. Such a stretching and coating sequence would be suitable for the production of coated linear polyester film substrates. The film is preferably first stretched longitudinally through a series of rotating rollers, coated and then stretched transversely in a tenter oven, preferably followed by heat setting. The coating composition is preferably applied to an already oriented film substrate, for example a film of biaxially oriented polyester, especially polyethylene terephthalate, which is preferably heated.

The temperature at which the coated film is heated depends, inter alia, on the set of polymer substrates. The coated polyester, especially polyethylene terephthalate, substrate is used in order to dry the solvent in compositions using an aqueous medium, or solvent, and to allow crosslinking of this layer to occur.
And again, it is appropriate to heat to 100-240 ° C, preferably 160-220 ° C, to help the film agglomerate and form a continuous, uniform layer. .. In contrast to this, the coated polyolefin,
In particular, polypropylene is suitably heated to 85 to 95 ° C.

The coating layer composition is preferably applied to the polymeric film substrate by any suitable conventional method. This conventional method is dip coating, bead
Coating, reverse roller coating or slot
There is application.

The coating weight of the coating layer on the polymer substrate is preferably 0.25 to 100 mgdm ^-2 , more preferably 0.5 to 40 mgdm ^-2 , and particularly preferably 1.0 to 20.0.
It is mgdm ^-2 . For films coated on both sides, the coating weight of such layers is in the preferred range.

In a preferred embodiment of this invention, an additional primer layer is applied to the substrate layer prior to coating with the layered mineral coating layer. The present invention provides a surprising improvement in oxygen barrier properties with the presence of the polymeric film primer.

Any polymer known in the art as capable of forming a continuous, preferably uniform coating, adherent to the supporting substrate, and preferably having optical clarity. At least one polymer resin,
The primer layer is included.

Suitable polymeric resins include the following:

(A) Alkoxylation condensation products of melamine and formaldehyde, typically "aminoplast, which can be prepared by reaction of an amine or amide with an aldehyde with hexamethoxymethylmelamine formaldehyde, trimethoxytrimethylolmelamine formaldehyde. "resin;

(B) homopolyesters such as polyethylene terephthalate;

(C) copolyesters, especially those derived from sulfo derivatives of dicarboxylic acids, such as those derived from sulfoterephthalic acid and / or sulfoisophthalic acid;

(D) Copolymers of styrene with one or more ethylenically unsaturated comonomers such as maleic anhydride or itaconic acid, especially GB-A-1540067.
The copolymers described in 1.

(E) Acrylic acid and / or methacrylic acid and / or their lower alkyl (C6 or less)
Copolymers of esters, such as copolymers of ethyl acrylate and methyl methacrylate, copolymers of methyl methacrylate / butyl acrylate / acrylic acid,
Typically with a molar ratio of 55/27/18% and 3
6/24/40%;

(F) Styrene / acrylamide copolymers, especially GB-A-1174328 and GB-A-1.
Of the type described in 134876;

(G) functionalized polyolefins, especially maleated polybutadiene;

(H) cellulosic materials such as nitrocellulose, ethyl cellulose and hydroxyethyl cellulose;

(I) Polyvinyl alcohol.

Preferred resin components of the primer layer are acrylamide and / or its derivatives, such as lower alkyl, preferably n-butoxy derivatives, and / or methacrylamide and / or its derivatives, such as lower alkoxy, preferably n-butoxy derivatives. , And at least one other ethylenically unsaturated comonomer copolymerizable therewith. Examples thereof are acrylic acid and its esters, such as alkyl esters, such as methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethyl-hexyl acrylate, isobutyl acrylate, hexyl acrylate and octyl acrylate; methacrylic acid and its esters, such as methyl. There are copolymers of methacrylate, ethyl methacrylate and butyl methacrylate. Other suitable monomers include acrylonitrile, styrene, monomethylstyrene, vinyltoluene, maleic anhydride and vinyl esters. Styrene and alkyl acrylates are particularly preferred monomers. Dienes such as butadiene or chloroprene may also be present in the primer layer copolymer.

The primer layer preferably contains at least one free functional acid group (eg a pendant carboxyl group, or a sulfonate group). This is a group that does not participate in the polymerization reaction forming the copolymer, for example acrylic acid, methacrylic acid, maleic acid and itaconic acid. Suitably up to 25% by weight, preferably up to 10% by weight and particularly preferably up to 5% by weight of free functional acid group-containing comonomers may be used.

The polymeric resin component of the primer layer is preferably up to 90% by weight styrene, up to 80% by weight alkyl acrylate, up to 15% by weight methacrylic acid and 5 to 40% by weight acrylamide in the copolymer. It contains a copolymer obtained from condensation of formaldehyde with butanol solution containing 0.2 to 3 g equivalents of formaldehyde for each amide group. A particularly preferred copolymer is styrene / 2-ethylhexyl acrylate / methacrylic acid / n-butoxymethyl acrylamide in a ratio of 20-40 / 30-50 / 1-5 / 20-.
30% by weight. GB-A-1174328 and GB-A-1134876 describe suitable synthetic methods for the primer layer copolymers described above.

The polymeric resin of the primer layer is preferably compatible with additional acidic components such as sulfuric acid, nitric acid, acetic acid or any mineral acid such as hydrochloric acid, including them in the primer layer coating composition. There is. The additional acidic component is preferably 0.5 to 15, more preferably 1 to 10, with respect to the polymer resin in the primer layer coating composition.
Particularly preferably it is present in a concentration of 4 to 8% by weight. Sulfuric acid is the preferred acidic component.

The molecular weight of the polymeric resin of the primer layer can vary over a wide range, but the weight average molecular weight is preferably 10,000 to 300,000, more preferably 1
It is 5,000 to 100,000.

The polymers of the primer layer coating composition are generally water insoluble. However, the primer layer composition containing the water-insoluble polymer can be applied to the polymer film substrate as an aqueous dispersion or organic solvent solution.

The primer layer coating material may be applied before, during or after the stretching operation. In particular, the coating material may be applied to the film substrate during the two stages of the biaxial stretching operation (longitudinal and transverse). Such a stretching and coating sequence is suitable for the production of coated linear polyester film substrates, such as coated polyethylene terephthalate film. This preferably involves stretching the film first through a series of rotating rollers in the machine direction, coating, then stretching in the tenter oven in the transverse direction, preferably followed by heat setting.

The primer layer coating composition is applied to the polymer film as an aqueous dispersion or an organic solvent solution by any suitable conventional coating method such as dip coating, bead coating,
It may be applied by either reverse roller coating or slot coating.

The primer layer coating material is preferably applied to already oriented film substrates, such as biaxially oriented polyester, especially polyethylene terephthalate film.

Prior to disposing the primer or coating layer on the polymeric substrate, if desired, the surface of the substrate may be subjected to a chemical or physical surface modification treatment to the surface and the primer or coating layer applied thereafter. Adhesion between and may be improved. The preferred treatment is to subject the surface of the substrate to high voltage electrical stress with corona discharge because of its simplicity and effectiveness, and which is particularly suitable for treating polyolefin substrates. Alternatively, the substrate may be pretreated with a treating agent known in the art to exert a solvent or swelling action on the substrate polymer. Examples of such treating agents, which are particularly suitable for treating polyester substrates, include halogenated phenols, such as p-chloro-m-cresol, 2,4-dichloro, dissolved in common organic solvents. Phenol,
Some are 2,4,5- or 2,4,6-trichlorophenol or 4-chlororesorcinol dissolved in acetone or methanol.

[0055] The primer layer is preferably coating weight 0.1～10Mgdm ^-1 to polymeric substrates, particularly 1.0～6Mgdm ^-1
Apply with. For films coated on both sides, each layer preferably has the above-preferred coating weight.

Surface modification of the primer layer, such as flame treatment, ion bombardment, electron beam treatment, UV treatment or preferably corona discharge treatment, will improve the adhesion of the coating layer containing subsequently applied layered minerals. However, it may not be essential to get a satisfactory bond.

The preferred treatment by corona discharge may be carried out in air at atmospheric pressure, with conventional equipment using a high frequency high voltage generator, preferably with a voltage of 1 to 100 KV and an output of 1 to 20 KW. The discharge is carried out at a linear velocity, preferably 1.0
It is convenient to pass through at ~ 500 m / min. The discharge electrode is 0.1 to 10.0 from the moving film surface.
May be located at mm.

The thickness of the primer layer relative to the thickness of the substrate can vary over a wide range, but the thickness of the primer layer is
It should preferably be not less than 0.004% and not more than 10% of that of the substrate. In fact, the thickness of the primer layer is desirably at least 0.005 μm, preferably 1.
It should not exceed 0 μm significantly.

An additional overcoat layer may be applied on top of the coating layer. The overcoat layer may be any suitable film-forming polymeric resin, such as those described herein for use in the primer layer.

The polymer films described herein are suitable as packaging films, especially when laminated with polyethylene films as overcoat layers. This polyethylene film is preferably adhered to the polymer film of the covering layer by means of an intermediate adhesive layer, in particular a polyurethane layer.

One or more of the layers of the polymeric film of the present invention, the substrate layer, the primer layer, the coating layer and / or the overcoat layer, comprises any of the additives conventionally used in the production of polymeric films. It is convenient to have Therefore, dyes, pigments, pore-forming agents, lubricants, antioxidants, antiblocking agents, surfactants, slip aids,
Gloss improver, prodegradant
ant), an ultraviolet stabilizer, a viscosity modifier, and a dispersion stabilizer may be appropriately added to the substrate and / or the coating layer. In particular, the substrate may include a particulate filler, such as small particle size silica. If a filler is used in the substrate layer, it should desirably be present in a minor amount of 0.5% or less, preferably 0.2% or less by weight of the substrate.

The present invention will be described with reference to the accompanying drawings.

FIG. 1 is a schematic cross-sectional view that is not proportional to the actual dimensions of a coating film having a base layer and a coating layer.

FIG. 2 is a similar schematic cross section of a coating film having an additional primer layer between the substrate layer and the coating layer.

FIG. 3 is a similar cross-sectional schematic view of the film shown in FIG. 2 with an additional overcoat on the remote surface of the cover layer.

In FIG. 1, the film comprises a polymeric substrate layer 1 having a coating layer bonded to one surface 3 thereof.

The film of FIG. 2 comprises an additional primer layer 4 bonded to the surface 3 of the substrate layer 1 and the surface 5 of the coating layer 2.

The film of FIG. 3 further comprises an additional overcoat layer 6 bonded to the remote surface 7 of the coating layer 2.

[0069]

The present invention will be further described with reference to the following examples.

The following test methods were used.

Adhesion Test The adhesion of the coating layer to the substrate, or that of the coating layer to the primer layer and that of the primer layer to the substrate was measured by the following method. Two strips of adhesive tape were placed on the cover layer of the film and adhered by rubbing the tape's back up and down three times. The first strip of adhesive tape was slowly peeled back (= delayed) at 180 ° to the peel edge. A second strip of adhesive tape was quickly peeled off directly from the film surface (= quick pull). Then, this film sample was observed with a light box, and the amount of the film removed was judged as good (= no damage to the film with the naked eye), normal (= some damage to the film), poor (= majority of the film). Are excluded), and evaluated as.

Oxygen Barrier Mocon ™ 1050 (Modern Cont)
rolls Inc. ) The oxygen permeability of the film was measured using a tester. A film sample was placed in the instrument and a nitrogen carrier gas was passed over the film on both the top and bottom to obtain a background reading. The nitrogen above the film was replaced with oxygen and the amount of oxygen that could permeate the film was measured in a carrier gas using a sensor.

Example 1 A vermiculite suspension was prepared by the following method:

100 g of vermiculite ore (ex-
Carolina, US) was refluxed with IN lithium citrate solution IL at 80 ° C. for 4 hours and left at room temperature for 5 days. This resulted in the exchange of 45.3 mg equivalents of lithium cations in 100 g of ore. The ion-exchanged vermiculite ore was washed 5 times with deionized water to remove excess salt and left overnight to swell in a large volume of deionized water (ie 10 times the volume of vermiculite). The swollen vermiculite was milled in a Greaves ™ high shear mixer for 40 minutes at 7200 rpm to form a suspension of vermiculite platelets. The platelet suspension was then sieved through a mechanically agitated filter with a pore size of 106 μm.

A polyethylene terephthalate film was melt extruded, cast on a cooled rotating drum and stretched in the direction of extrusion to about 3 times its original size. The film was passed through a tenter oven where it was stretched in the width direction to about 3 times its original dimensions. This biaxially stretched film was heat set at about 220 ° C. by a conventional method. The final film thickness was 23 μm.

One side of this biaxially oriented polyethylene terephthalate film was coated with a coating layer composition comprising the following components using a gravure coater:

[Table 1] Vermiculite 16L (7.5% w / w aqueous dispersion) Cymel (trademark) 385 800mL (melamine formaldehyde having a molecular weight of 348) Paratoluene sulfonic acid 100mL (10% w / w aqueous solution) Synperonic (trademark) ) NP 10 150 mL (10% w / w aqueous solution of nonylphenol ethoxylate (sold by ICI)) Deionized water 20 L

The coated film was dried at 180 ° C. and
The dry coating weight of the coating layer is about 2 mgdm ^-2Met. This cover
The thickness of the cover layer was about 0.1 μm.

The adhesion of the coating layer to the substrate was measured using the adhesion test described above and was "good" for both slow and fast pulls.
Met.

The oxygen barrier property of the coated film was measured by measuring the oxygen permeability to be 9.5 cc.
/ M ² / day. The oxygen permeability of the uncoated polyethylene terephthalate film was also measured and found to be 50.0cc.
/ M ² / day.

Example 2 The process of Example 1 was repeated except that one side of the biaxially oriented polyethylene terephthalate film was first coated with the primer layer material. This primer layer material stock solution contains 50% by weight of polymer,
Weight ratio 30.9 / 38.9 / in a solvent mixture of n-butanol / toluene / xylene in the ratio 19/78/3.
2.1 / 28.1 styrene / ethylhexyl acrylate / methacrylic acid / n-butoxymethyl acrylamide was dissolved. Prior to coating, the primer layer material stock solution was diluted to 4% by weight with isopropyl alcohol and 6% by weight of polymer of sulfuric acid was added. This primer layer material was coated using a gravure coater. After coating, the film was dried in a hot air oven maintained at 90 ° C to give a dry film weight of 1.0 mgdm ^-2 and a thickness of about 0.
A film with a 1 μm primer layer was obtained.

Then, the coating layer composition described in Example 1 was coated on the primer layer of the polyethylene terephthalate film coated with this primer layer.

When the adhesiveness of the coating layer to the primer layer and the adhesiveness of the primer layer to the substrate were measured by the above-mentioned adhesion test, both the delayed delay and the accelerated delay were “good”.

When the oxygen barrier property of the film was measured by measuring the oxygen permeability, it was 0.5 cc / m ² / day.

Example 3 This example is a comparative example not according to the present invention. The procedure of Example 2 was repeated except that the coating composition did not contain Cymel 385 and paratoluene sulfonic acid.

When the adhesiveness of the coating layer to the primer layer and the adhesiveness of the primer layer to the substrate were measured by the above-mentioned adhesion test, both the delayed delay and the accelerated delay were “poor”.

Example 4 The procedure of Example 1 was repeated except that the coating layer composition consisted of the following ingredients:

Table 2 HTS-SE 8L (8.3% w / w aqueous dispersion of vermiculite containing 5% by weight of ethylene / vinyl acetate copolymer with respect to vermiculite (according to inventor's analysis), WR Grace, Massachusetts) Cymel ™ 385 450 mL (molecular weight 348 melamine formaldehyde) Paratoluene sulfonic acid 180 mL (10% w / w aqueous solution) Synperonic ™ NP 10 200 mL (nonylphenol ethoxylate (obtained from ICI). 10% w / w aqueous solution) 20 L of deionized water

The adhesion of the coating layer to the substrate was measured by using the above-mentioned adhesion test, and both the delayed pulling and the rapid pulling were “good”.

Furthermore, the adhesion strength of the coating layer to the substrate was measured in an additional test. In this test, gravure-based and polyurethane adhesive (polyurethane prepolymer (Product No. 1
0-2525 / 3) and polyhydric alcohol (Product No. 1)
0-2526 / 3, All Holden Surfa
ce Coatings Ltd, obtained from England). ) Was used to coat the coating layer and dried in an oven at 80 ° C., and two of this film and the polyethylene film were passed through a nip roller heated to 120 ° C. to laminate the polyethylene film. The resulting laminate was peeled off at a peel speed of 200 mm / min using an "Instron" test meter to measure adhesion. Peel strength is 250g / 25mm
(98 Nm ^-1 ). On the other hand, the laminate formed using the coating film prepared in Example 1 has a peel strength of 1
It was 0 g / 25 mm (3.9 Nm ^-1 ).

The above example illustrates the improved properties of the coated film of the present invention.

Preferred features

As noted herein, the polymeric films of the present invention exhibit the following preferred features-independently or in any combination.

1. The coating layer comprises more than 20% of the weight of this layer,
Layered minerals less than 80% and more than 20% of the weight of this layer, 8
It contains less than 0% of resin obtained from the crosslinker.

2. The coating layer additionally comprises a copolymer of 1-olefin and vinyl monomer.

3. The cross-linking agent has a molecular weight of less than 2000.

4. Layered minerals include film-forming 2: 1 phyllosilicate platelets.

The 5.2: 1 phyllosilicate consists of vermiculite.

6. There is a primer layer containing a polymeric resin between the substrate and the coating layer.

7. The primer layer is acidic.

8. The primer layer is acrylamide and /
Or a derivative thereof and / or methacrylamide and / or a derivative thereof, and a copolymer of at least one other ethylenically unsaturated comonomer copolymerizable therewith.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view that is not proportional to the actual dimensions of a coating film having a base layer and a coating layer.

FIG. 2 is a similar schematic cross-sectional view of a coating film having an additional primer layer between the base layer and the coating layer.

3 is a similar cross-sectional schematic diagram of the film shown in FIG. 2 with an additional overcoat on the remote surface of the coating layer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Polymer substrate layer 2 ... Coating layer 3 ... One surface of the polymer substrate layer 1 ... Additional primer layer 5 ... Surface of coating layer 2 6 ... Overcoat layer

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor William Neville Eugene Meredith tees, England 68, Jay, Cleveland, Middlesbrough, Wilton, Peau Box 90 (72) Inventor David Edward Higgins tees, England 68 Jay, Cleveland, Middlesbrough, Wilton, Peobox 90

Claims (2)

[Claims] 1. A substrate layer of polymeric material has a coating layer formed on at least one surface thereof from a composition containing a layered mineral and a resin obtained from a cross-linking agent, said coating layer comprising:
A polymer film comprising more than 0% and less than 90% by weight of a layered mineral layer and more than 10% and less than 90% by weight of a resin layer obtained from a crosslinking agent. 2. A base layer of polymeric material is formed, and a coating layer formed from a composition containing a layered mineral and a resin obtained from a cross-linking agent is applied to at least one surface of the base layer, the coating layer being 10 A method for producing a polymer film, comprising a layer of layered mineral of greater than wt%, less than 90 wt% and a resin layer obtained from more than 10 wt% of less than 90 wt% crosslinker.